The report says that Apple relies on "dirty data" centers. It reveals that the company's investment in a new North Carolina facility will increase its electricity consumption threefold, that would be equivalent to the electricity demand of 80,000 average US homes. The complex's power will be provided by Duke Energy, they’ll use a mix of 62% coal and 32% nuclear.

Gary Cook, Greenpeace's IT policy analyst and lead author of the report, said: "Consumers want to know that when they upload a video or change their Facebook status that they are not contributing to global warming or future Fukushimas."

US companies are not required by law to reveal their energy use or carbon emissions.

However, Greenpeace found publicly available information on investments made in data centers, this allowed them to estimate the maximum power these facilities will use, and they matched that information with data from the government or utilities.

The report projected dependence on coal for Apple's data centers to be at 54.5%, second was Facebook at 53.2%, IBM at 51.6%, HP at 49.4%, and Twitter at 42.5%. The best performers in Greenpeace's clean energy index were Yahoo, followed by Google and Amazon. Greenpeace is also asking for Facebook to "unfriend coal" and use cleaner energy to fuel its servers.

Cook said: "Many companies treat their energy consumption a bit like the Coca-Cola secret formula, because they don't want competitors knowing how much they spend on energy. The amount of electricity they consume would give some indication of what kind of arms race they were in. They don't really want this story to be told."

Luckily Greenpeace told the story themselves, the ecowarriors of the world must be proud.

Cloud computing depends on large data centers, rather than in-house based IT services, to power Internet-based services such as Hotmail or Gmail. Data center energy demand already makes up 1.5% to 2% of world electricity consumption and it’s said that it will quadruple over the next 10 years.

Molly Webb, head of smart technology at the Climate Group in London, said: "Greenpeace is calling for transparency from companies which rely heavily on data centers, and that would ideally highlight the need for investment and ambitious government policy to ensure enough clean power is available to green our tweets."

Green our tweets? (Wow. I don’t like the way you talk Molly Webb.)

Apple didn’t comment on the Greenpeace report, but is likely to have more to say about the data center in Maiden, North Carolina, this spring.